Large-Format 3D-Printed Carbon Fiber-Reinforced Composites in Tooling Applications

Screw extrusion-based large-format additive manufacturing is a rapidly growing manufacturing solution for CFRP molds for the aerospace and motorsport industry. It ensures significant weight and time savings compared with the conventional technologies. This study provides a concise yet comprehensive framework for large-format 3D-printed tool design and manufacture, investigating the most industrially relevant materials. Acrylonitrile butadiene styrene (ABS), polycarbonate (PC), and polyetherimide (PEI) reinforced with 20 wt% of carbon fiber were selected. The print setup was based on a 10 kg/h extruder unit to deposit a 2 mm-thick 8 mm-wide strand. Characterization of printed samples was performed to highlight the process-induced print anisotropy. The influence of deposition temperature on longitudinal and transversal tensile samples was used to determine the material’s optimal processing window. Higher deposition temperatures promote layer adhesion, reaching 40–60% of the longitudinal properties. Thermomechanical analyses defined the optimal materials service temperature ranges. Oriented carbon fiber content restricts thermal expansion along the print direction by a factor of 10 compared to the transversal one, thus reducing part warpage during printing. Thermal expansion coefficients at common service temperatures are also provided. Finally, a real tool manufacturing case study and post-processed surface qualification are reported.